Effects of Different Simple Cultivation Facilities on Yield and Quality of Over-summer Brassica campestris L. in South China

The effects of different simple cultivation facilities on yield and quality of Brassica campestris L. were compared to explore the optimal facility type for pro- duction of B. campestris, thereby providing a technical reference for efficient cultiva- tion of B. campestris during hot season. A total of four treatments were designed, open field cultivation （CK）, ordinary anti-insect net shed cultivation, ordinary plastic film greenhouse cultivation and Japanese translucent anti-insect net shed cultivation. The results showed that compared with those in open field cultivation, the plant height, leaf area, yield, Vc content, soluble sugar content and soluble protein con- tent of B. campestris in Japanese translucent anti-insect net shed cultivation were increased by 22%, 63%, 49%, 14%, 13% and 10%, respectively, and Japanese translucent anti-insect net shed was the optimal facility type for cultivation of B. campestris in hot season.

Effects of Pruning Treatments on Yield and Economic Benefits of Pepper in Greenhouse during Long-season Cultivation

In the Yangtze River region, thepepper long-season cultivation needs oversummer pruning. Inorder to study the effects of different pruning treatments on growth of over-summer grown pepper, three differentpruning treatments were applied to pepper seedlings, such as treatment one（re-growth pruning）, treatment two（four stems） and treatment three（multi-stem pruning） with no pruning as control（CK）.The results showed that themulti-stem pruning treatment enabling the plant to maintain the good plant type for high yield and reduce thevirus disease to improve the marketability of pepper fruits, compared with the other two pruning treatments;andthe yield and economic benefit were increased by 15.8% and 19%, compared with the control, respectively. Ingeneral the multi-stem pruning was the best for over-summer pepper cultivation.

Annual variation in Calanus sinicus abundance and population structure in the northern boundary area of the Yellow Sea Cold Water Mass

The Yellow Sea Cold Water Mass （YSCWM） was suggested as an over-summering site of the dominant copepod species Calanus sinicus in coastal Chinese seas. Population abundance and structure were investigated by monthly sampling along three transects across the northern boundary of the YSCWM during 2009-2010. Results show that thermal stratification existed from June to October and that the vertical thermal difference increased with depth. Generally, total abundance was lowest in October and highest in June, and the female/male sex ratio was highest in February and lowest in August. Evident spatial differences in abundance were observed during the existence of the YSCWM. In June, total abundance averaged 158.8 ind/m~ at well-stratified stations, and 532.1 ind/m3 at other stations. Similarly, high abundances of 322.0 and 324.4 ind/m3 were recorded from July to August inside the YSCWM, while the abundance decreased from 50.4 to 1.9 ind/m3 outside the water mass. C. sinicus distribution tended to even out over the study area in September when the YSCWM disappeared. We believe that the YSCWM may retard population recruitment in spring and preserve abundant cohorts in summer. The summer population was transported to neritic waters in autumn. In addition to low temperatures, stable vertical structure was also an essential condition for preservation of the summer population. C. sinicus can survive the summer in marginal areas in high abundance, but the population structure is completely different in terms of C5 proportion and sex ratio.

Effect of diurnal temperature difference on lipid accumulation and development in Calanus sinicus(Copepoda:Calanoida)

Calanus sinicus,the dominant copepod in the Yellow Sea,develops a large oil sac in late spring to prepare for over-summering in the Yellow Sea Cold Water Mass(YSCWM).The lipid accumulation mechanism for the initiation of over-summering is unknown.Here,we cultured C3 copepodites at four constant temperatures(10,13,16,and 19℃) and at three temperature regimes that mimicked the temperature variations experienced during diurnal vertical migration(10-13℃,10-16℃,and 10-19℃) for 18 days to explore the effects of temperature differences on copepod development and lipid accumulation.C.sinicus stored more lipid at low than at high temperatures.A diurnal temperature difference(10-16℃ and 10-19℃)promoted greater lipid accumulation(1.9-2.1 times) than a constant temperature of either 16℃ or 19℃,by reducing the energy cost at colder temperatures and lengthening copepodite development.Thereafter,the lipid reserve supported gonad development after final molting.Only one male developed in these experiments.This highly female-skewed sex ratio may have been the result of the monotonous microalgae diet fed to the copepodites.This study provides the first evidence that diurnal temperature differences may promote lipid accumulation in C.sinicus,and provides a foundation for future investigations into the mechanisms involved in over-summering in the YSCWM.

Comparison Test on Adaptability of Six Medicago sativa (Alfalfa) Varieties in Guangxi

In order to screen the Medicago sativa(alfalfa)varieties suitable for planting in Guangxi,six domestic and foreign heat-resistant alfalfa varieties,namely WL903,WL712,WL525HQ,59N59,Elite 9 and Longwei 6010,were selected and tested for growth performance,nutritional value and over-summer rate by the random block method.The results showed that the alfalfa varieties with better plant height and fresh grass yield were 59N59 and WL903,which showed the plant heights reaching 62.01 and 62.53 cm,respectively,and the fresh grass yields up to 40.93 and 38.38 t/hm 2,respectively,exhibiting extremely significant differences from the poorly performing Longwei 6010(P<0.01).The nutritional value of each tested variety was good,and the crude protein content was more than 20%.Among them,Elite 9 had a crude protein content as high as 28.43%.The over-summer rates of the six alfalfa varieties were all higher than 75%.It showed that the alfalfa varieties with fast growth,high yield,high nutritional value and high over-summer rate in this experimental area were 59N59 and WL903,which are suitable as the first varieties for planting in Guangxi.