Effects of Meteorological Conditions on Yield and Quality of Facility Hami Melon

With different varieties of facility Hami melon(Cucumis melo var. sacchairinus) as test materials, the effects of meteorological conditions on the yield and quality of different varieties of facility Hami melon were analyzed. The results showed that among the yield and quality traits of melon, the variation degree of average single melon weight was the highest, and the coefficient of variation was 33.05%. The variation degree of leaf area index was the lowest, and the coefficient of variation was 11.00%. Through the correlation analysis of meteorological factors with the yield and quality of facility Hami melon, it was found that the quality traits of facility Hami melon were significantly positively correlated with maximum temperature and sunshine duration, and significantly negatively correlated with precipitation. The yield traits were positively correlated with maximum temperature, sunshine duration and precipitation.

The Study of Allelochemicals of the Melon Fly (Myiopardalis pardalina Bigot.)

This study describes the isolation, identification of allelochemicals of the melon fly (Myiopardalis pardalina Bigot.), using the GC-MS method. A food attractant has been identified and a method for the synthesis of its synthetic analogue has been developed. Also, a route for the synthesis of para pheromone, raspberry ketone, has been proposed.

Inhibitive Mechanisms of Two Silicon Compounds on Powdery Mildew of Melon

Seedlings of Yujinxiang melon were used to investigate the effect and inhibitive mechanism of sodium silicate and nanosized silicon oxide on powdery mildew. The results showed that the severity of powdery mildew on melon seedlings was lowered significantly by treatment with either of the two silicon compounds, although the effect of sodium silicate was more powerful than silicon oxide. Application of sodium silicate to the seedlings caused significant increases in the activity of peroxidase (POD) and of β-1,3-glucosidase (GLU), both enzymes are known to be associated with the disease defence systems of plants. SEM-EDX analysis of sodium silicate-treated leaves of the melon seedlings showed an elevated level of silicon deposit at stomata and epidermis. Treatment with nanosized silicon oxide also resulted in a similar increase in silicon deposit, but the treatment did not cause a significant increase in POD activity.

Modeling Study of Fruit Morphological Formation in Melon

Modeling of fruit morphological formation in melon is important for realizing virtual and digital plant growth.The objective of this study was to characterize the changes in patterns of fruit growth characters during plant development.In cultivar experiments,a high-resolution wireless vision sensor network has been developed to realize non-contact automatic uninterrupted measurement of the fruit shape micro-change （fruit size,color,and net）.Results showed that the fruit swelling process （vertical and horizontal diameters） exhibited a slow-rapid-slow pattern,which could be well described with a logistic curve against growing degree days （GDD）;fruit color changes based on the RGB values could be represented by quadratic relationship to cumulative GDD;the fruit net changes over growth progress could be partitioned into three phases according to the time interval.The first phase was from 1 to 30 days after pollination （DAP）,in which the vertical stripe appeared at fruit middle part and the horizontal stripe at fruit petiole and hilum part as well;the second phase was from 30 to 40 DAP,the horizontal stripe occurred at fruit middle part and the net was formed;the third phase was the process started from 40 DAP,the netted breadth and thickness were gradually increased.The model was validated with the independent data from the experiment,and the mean RMSE （root mean square error） of fruit were 0.36 and 0.28 cm for vertical and horizontal diameters,11.9 for fruit color,and 0.45 cm for stripe length and diameter at varied GDD,respectively.This work is beneficial to a reliable foundation for study the relationship between morphological formation and physiological change of the melon fruit internally and then realize the intelligent precision management to improve the yield and quality of greenhouse melon production.