Watercress was grown in uncovered tanks (30 cm deep) of non-circulating nutrient solution with an... more Watercress was grown in uncovered tanks (30 cm deep) of non-circulating nutrient solution with an EC of 1.0 to 1.8 mS in a polyethylene-covered rainshelter at an elevation of 1300 m. Additional nutrient solution was added to replace evaporation and transpiration, but no other adjustments or amendments were made. Shading with 57 and 71% saran shade significantly reduced moderately severe tipburn that occurred on non-shaded plants even though these plants experienced light reduction of 15% from the rainshelter roof. Monthly harvests were taken. The highest yields were obtained when a complete nutrient solution change was made after completion of the second harvests. Yield increased 25% and 68% by changing the nutrient solution every 2 months as compared to changing nutrient solution every 4 months and 6 months, respectively. B, Mg, Na and pH increased and nitrate-N, P, Ca, Cu, Fe and Mn decreased as the time period between nutrient solution changes increased. This contributed to lower...
Potatoes were grown in a polyethylene-covered rainshelter at an 850 m elevation in Hawaii. Nutrie... more Potatoes were grown in a polyethylene-covered rainshelter at an 850 m elevation in Hawaii. Nutrient solution (1.5 mS) depths of 2.5 to 5 cm were maintained in growing tanks (3.7 m long x 0.6 m wide) by gravity flow to float valves. Two 'Catalina' potato tubers were planted in bottom-perforated polyethylene bags supported by the tank floor and 3 tubers were planted in nursery trays (17x17x5 cm) elevated 5 cm above the tank floor. The bags and trays contained 2 liters of growing medium per potato seed tuber and these containers were subsequently 'hilled' 3 times with dry grass. Total salable yields of potatoes growing in nursery trays and 11.4 and 18.9-liter bags were 5.4, 4.6 and 5.1 kg/m 2 (based upon tank area), respectively. In another experiment, no significant yield differences were observed from 'All Blue' and 'Catalina' potatoes which were grown similarly in 18.9-liter bags, in 10-cm slit-sided pots supported by a 2.5 cm-thick expanded polystyre...
Big Beef' tomatoes produced 2.68 kg/plant from a 72 day harvest period when they were grown i... more Big Beef' tomatoes produced 2.68 kg/plant from a 72 day harvest period when they were grown in 0.35 liter aluminum beverage cans by a sub-irrigation hydroponic method. Tomatoes growing in net pots (70 ml) suspended by expanded polystyrene bead boards with a sub-irrigation method gave similar yields in one trial but lower yields in another trial than tomatoes growing in beverage cans. Tomatoes growing in 10 cm square plastic pots filled with perlite (700 ml) rested on 5 cm high upside-down nursery trays and yielded significantly higher than plants growing in aluminum beverage cans resting on the tank floor in 2 trials. Placing a 5 cm high nursery tray as a support for a 10 cm pot increases the root exposure to moist air (i.e. air between the nutrient solution surface and the tank cover) and provides a net-type surface which encourages root formation and anchorage. Hawaii's lower elevations are warm and very conducive to mosquito reproduction in these non-circulating hydroponi...
Edible ginger (Zingiber officinale) is a spice and vegetable crop produced on the Island of Hawai... more Edible ginger (Zingiber officinale) is a spice and vegetable crop produced on the Island of Hawaii. It is asexually propagated from rhizomes, called seed pieces, which are saved from a previous crop. Bacterial wilt (Ralstonia solanacearum race 4) causes severe yield losses of edible ginger. Many ginger fields are infested with Ralstonia and there is a high risk that ginger seed pieces collected from these fields will be infected with the pathogen. Two growing methods were developed to produce rhizomes that are free from Ralstonia. Clean ginger seed pieces that originated from tissue cultured plants were grown using hydroponic methods for 8 successive crop cycles. First, ginger pieces were grown in 26L pots. To conserve growing medium and increase aeration, an upside-down 3L pot was placed on the bottom of the larger pot. Three 50g seed pieces were planted in a 26L pot that was filled with peat mix: medium perlite: coir (1:1:1, v:v:v). Pots were placed in elevated polyethylene-lined ...
808-956-7036. The university is an equal opportunity/affirmative action institution providing pro... more 808-956-7036. The university is an equal opportunity/affirmative action institution providing programs and services to the people of Hawai'i without regard to race, sex, gender identity and expression, age, religion, color, national origin, ancestry, disability, marital status, arrest and court record, sexual orientation, or status as a covered veteran. Find CTAHR publications at www.ctahr.hawaii.edu/freepubs. Introduction The purpose of this study was to determine the effects of 4 shading levels on the yield of edible ginger rhizomes which were grown in sub-irrigated pots under plastic-covered rainshelters. Temporary wilting of edible ginger foliage (Zingiber officinale Roscoe) has been observed at mid-day during hot, sunny weather conditions (Figure 1). Wilted plants generally have lower photosynthetic rates than normally turgid plants, and this usually reduces crop yields. Shading of crops typically allevi-ates foliage wilting, because shad-ing reduces leaf temperatures as we...
808-956-7036. The university is an equal opportunity/affirmative action institution providing pro... more 808-956-7036. The university is an equal opportunity/affirmative action institution providing programs and services to the people of Hawai'i without regard to race, sex, gender identity and expression, age, religion, color, national origin, ancestry, disability, marital status, arrest and court record, sexual orientation, or status as a covered veteran. Find CTAHR publications at www.ctahr.hawaii.edu/freepubs. I n Hawai'i, the primary limiting factor for the commer-cial production of edible ginger is the disease known as bacterial wilt (caused by Ralstonia solanacearum race 4) (Hepperly et al. 2004). First reports of this disease in Hawai'i were made in 1964, with subsequent crop losses reported as high as 60% in 1993 (Ishii and Aragaki 1963, Rohrbach et al. 1993). Symptoms of bacterial wilt of ginger include leaf yellowing and curling followed by necrosis and lethal wilting of the plant (Figure 1). Since ginger is vegetatively propagated, it is important to plant seed p...
Watercress was grown in uncovered tanks (30 cm deep) of non-circulating nutrient solution with an... more Watercress was grown in uncovered tanks (30 cm deep) of non-circulating nutrient solution with an EC of 1.0 to 1.8 mS in a polyethylene-covered rainshelter at an elevation of 1300 m. Additional nutrient solution was added to replace evaporation and transpiration, but no other adjustments or amendments were made. Shading with 57 and 71% saran shade significantly reduced moderately severe tipburn that occurred on non-shaded plants even though these plants experienced light reduction of 15% from the rainshelter roof. Monthly harvests were taken. The highest yields were obtained when a complete nutrient solution change was made after completion of the second harvests. Yield increased 25% and 68% by changing the nutrient solution every 2 months as compared to changing nutrient solution every 4 months and 6 months, respectively. B, Mg, Na and pH increased and nitrate-N, P, Ca, Cu, Fe and Mn decreased as the time period between nutrient solution changes increased. This contributed to lower...
Potatoes were grown in a polyethylene-covered rainshelter at an 850 m elevation in Hawaii. Nutrie... more Potatoes were grown in a polyethylene-covered rainshelter at an 850 m elevation in Hawaii. Nutrient solution (1.5 mS) depths of 2.5 to 5 cm were maintained in growing tanks (3.7 m long x 0.6 m wide) by gravity flow to float valves. Two 'Catalina' potato tubers were planted in bottom-perforated polyethylene bags supported by the tank floor and 3 tubers were planted in nursery trays (17x17x5 cm) elevated 5 cm above the tank floor. The bags and trays contained 2 liters of growing medium per potato seed tuber and these containers were subsequently 'hilled' 3 times with dry grass. Total salable yields of potatoes growing in nursery trays and 11.4 and 18.9-liter bags were 5.4, 4.6 and 5.1 kg/m 2 (based upon tank area), respectively. In another experiment, no significant yield differences were observed from 'All Blue' and 'Catalina' potatoes which were grown similarly in 18.9-liter bags, in 10-cm slit-sided pots supported by a 2.5 cm-thick expanded polystyre...
Big Beef' tomatoes produced 2.68 kg/plant from a 72 day harvest period when they were grown i... more Big Beef' tomatoes produced 2.68 kg/plant from a 72 day harvest period when they were grown in 0.35 liter aluminum beverage cans by a sub-irrigation hydroponic method. Tomatoes growing in net pots (70 ml) suspended by expanded polystyrene bead boards with a sub-irrigation method gave similar yields in one trial but lower yields in another trial than tomatoes growing in beverage cans. Tomatoes growing in 10 cm square plastic pots filled with perlite (700 ml) rested on 5 cm high upside-down nursery trays and yielded significantly higher than plants growing in aluminum beverage cans resting on the tank floor in 2 trials. Placing a 5 cm high nursery tray as a support for a 10 cm pot increases the root exposure to moist air (i.e. air between the nutrient solution surface and the tank cover) and provides a net-type surface which encourages root formation and anchorage. Hawaii's lower elevations are warm and very conducive to mosquito reproduction in these non-circulating hydroponi...
Edible ginger (Zingiber officinale) is a spice and vegetable crop produced on the Island of Hawai... more Edible ginger (Zingiber officinale) is a spice and vegetable crop produced on the Island of Hawaii. It is asexually propagated from rhizomes, called seed pieces, which are saved from a previous crop. Bacterial wilt (Ralstonia solanacearum race 4) causes severe yield losses of edible ginger. Many ginger fields are infested with Ralstonia and there is a high risk that ginger seed pieces collected from these fields will be infected with the pathogen. Two growing methods were developed to produce rhizomes that are free from Ralstonia. Clean ginger seed pieces that originated from tissue cultured plants were grown using hydroponic methods for 8 successive crop cycles. First, ginger pieces were grown in 26L pots. To conserve growing medium and increase aeration, an upside-down 3L pot was placed on the bottom of the larger pot. Three 50g seed pieces were planted in a 26L pot that was filled with peat mix: medium perlite: coir (1:1:1, v:v:v). Pots were placed in elevated polyethylene-lined ...
808-956-7036. The university is an equal opportunity/affirmative action institution providing pro... more 808-956-7036. The university is an equal opportunity/affirmative action institution providing programs and services to the people of Hawai'i without regard to race, sex, gender identity and expression, age, religion, color, national origin, ancestry, disability, marital status, arrest and court record, sexual orientation, or status as a covered veteran. Find CTAHR publications at www.ctahr.hawaii.edu/freepubs. Introduction The purpose of this study was to determine the effects of 4 shading levels on the yield of edible ginger rhizomes which were grown in sub-irrigated pots under plastic-covered rainshelters. Temporary wilting of edible ginger foliage (Zingiber officinale Roscoe) has been observed at mid-day during hot, sunny weather conditions (Figure 1). Wilted plants generally have lower photosynthetic rates than normally turgid plants, and this usually reduces crop yields. Shading of crops typically allevi-ates foliage wilting, because shad-ing reduces leaf temperatures as we...
808-956-7036. The university is an equal opportunity/affirmative action institution providing pro... more 808-956-7036. The university is an equal opportunity/affirmative action institution providing programs and services to the people of Hawai'i without regard to race, sex, gender identity and expression, age, religion, color, national origin, ancestry, disability, marital status, arrest and court record, sexual orientation, or status as a covered veteran. Find CTAHR publications at www.ctahr.hawaii.edu/freepubs. I n Hawai'i, the primary limiting factor for the commer-cial production of edible ginger is the disease known as bacterial wilt (caused by Ralstonia solanacearum race 4) (Hepperly et al. 2004). First reports of this disease in Hawai'i were made in 1964, with subsequent crop losses reported as high as 60% in 1993 (Ishii and Aragaki 1963, Rohrbach et al. 1993). Symptoms of bacterial wilt of ginger include leaf yellowing and curling followed by necrosis and lethal wilting of the plant (Figure 1). Since ginger is vegetatively propagated, it is important to plant seed p...
Uploads
Papers by Bernard Kratky