Near-infrared Reflective Diffusion Coating Is Beneficial for Asparagus Summer Production in a Simple Plastic Greenhouse

AbstractThe pea aphid, Acyrthosiphon pisum (Harris), affected yield by significantly reducing the mean height of aphid-susceptible Grimm alfalfa in a greenhouse experiment by 45%, the height of the longest stem by 35%, the green weight by 38%, the dry weight by 44%, and the fiber by 13%. There was limited change in quality of alfalfa. The percentages of protein, fat, total sugar, reducing sugar, dry matter, and nitrogen-free extract were not significantly different in the infested and non-infested alfalfa. Potassium was significantly lower in the infested plants but they contained more calcium, magnesium, and phosphorus. With the exception of isoleucine the amino acid composition was similar in the infested and non-infested alfalfa.

In order to determine the proper irrigation amount of summer tomatoes,taking drip irrigation in green house,5 irrigation volume including 990 m3/hm2、1485 m3/hm2、1980 m3/hm2(CK)、2475 m3/hm2、2970 m3/hm2 were set,and the effects of different irrigation amount on the yield and quality of tomato in greenhouse were studied. The results showed that with the increase of irrigation amount,the soluble solid content,titratable acid content,Vc content and irrigation water use efficiency of tomato decreased. In treatment T1, T4, T5 ,yield decreased by 26.3%, 6.5%, 15.8%. In treatment T2 , the yield decreased by 1.9%,while the irrigation water use efficiency increased by 20.8%,and the soluble solids content,titratable acid content and Vc content increased.It is concluded that the optimum irrigation amount is 1485 m3/hm2.

Insufficient light in autumn–winter may prolong the production periods and reduce the quality of plug seedlings grown in greenhouses. Additionally, there is no optimal protocol for supplementary light strategies when providing the same amount of light for plug seedling production. This study was conducted to determine the influences of combinations of supplementary light intensity and light duration with the same daily light integral (DLI) on the morphological and physiological properties of cucumber seedlings (Cucumis sativus L. cv. Tianjiao No. 5) grown in a greenhouse. A supplementary light with the same DLI of 6.0 mol m−2 d−1 was applied with the light duration set to 6, 8, 10, or 12 h d−1 provided by light-emitting diodes (LEDs), and cucumber seedlings grown with sunlight only were set as the control. The results indicated that increasing DLI using supplementary light promoted the growth and development of cucumber seedlings over those grown without supplementary light; however, opposite trends were observed in the superoxide dismutase (SOD) and catalase (CAT) activities. Under equal DLI, increasing the supplementary light duration from 6 to 10 h d−1 increased the root surface area (66.8%), shoot dry weight (24.0%), seedling quality index (237.0%), root activity (60.0%), and stem firmness (27.2%) of the cucumber seedlings. The specific leaf area of the cucumber seedlings decreased quadratically with an increase in supplementary light duration, and an opposite trend was exhibited for the stem diameter of the cucumber seedlings. In summary, increased DLI or longer light duration combined with lower light intensity with equal DLI provided by supplementary light in insufficient sunlight seasons improved the quality of the cucumber seedlings through the modification of the root architecture and stem firmness, increasing the mechanical strength of the cucumber seedlings for transplanting.

The yield and quality of a diverse range of cotton hybrids was measured in one, or more, of a number of experiments conducted in the Ord River valley, Western Australia (15�S.) and the Namoi River valley, New South Wales (30�S.). Two of the experiments were diallels, one involving nine parents, the other thirteen parents. In both the plant and subsequent ratoon crops, mean yield of the hybrids was significantly greater than the mean yield of the parents, and the hybrids had significantly longer and stronger fibre. A few hybrids in both diallels significantly outyielded commercial controls by between 15 and 35% in both the plant and ratoon crops. Subsequently, in other experiments including one with near-commercial large plots, the high performers from the diallel experiments were inconsistent for yield, usually exhibiting little or no heterosis above that of the best commercial cultivars. Other hybrids tested in these experiments also generally failed to outyield the commercial controls, although a number had higher-quality fibre. It was concluded the heterosis for yield is not consistent enough under high-yielding Australian conditions to warrant the commercial production of hybrid cotton seed. Some hybrids, however, especially the interspecific G. hirsutum x G. barbadense ones, have the stronger, finer fibre that appears better suited to cotton spinning equipment now being developed, and this aspect could justify reappraisal of this conclusion in the future.

A field experiment was carried out during rabi 2010-11 to study the growth, yield and quality of gram as influenced by irrigation and sulphur levels. Irrigation and sulphur have shown significant influence on growth, yield, quality, moisture extraction pattern and water use efficiency. Among four irrigation schedules, irrigation scheduled at 0.9 IW/CPE ratio recorded higher values for all the growth parameters at various stages, yield attributes, grain and stover yield, quality parameters as well as net return and BCR while, 0.7 IW/CPE ratio remained on par. Amount of moisture extracted from surface layers was more irrespective of irrigation treatment. Depletion of soil moisture increased and water use efficiency decreased with increasing frequency of irrigation. Application of 40 kg S ha-1 recorded higher grain yield, protein content and protein yield, net return and BCR and remained on par with 20 kg S ha-1. However interaction between sulphur and irrigation levels, 20 kg S ha-1 and 0.7 IW/CPE has reported higher seed yield, net returns and BCR.

SUMMARYThe effects of three irrigation regimes on growth, yield and quality of cotton were investigated for two seasons in relation to earliness, quality and water-use efficiency, expressed as m. of water/kg. cotton produced. Light irrigations of cotton, at 75 mm. per irrigation every ten days, were economically better than the traditionally-accepted practice of irrigating every 14 days, and markedly better than prolonging the irrigation cycle to 20 days, mainly due to increased market value of the crop. The results also showed that irrigation intervals of 20 days, besides depressing yield, had a deleterious effect on fibre strength, though the different water regimes did not seem to affect other quality tests.