Organic Cultivation of Summer-Autumn Cucumbers in Mixed Cropping with Balsam Pears (Momordica Charantia)

Abstract

Summer-autumn cucumbers were organically grown in Kofu basin of Yamanashi Prefecture. In the organic cultivation, the yield and ratio of high quality cucumbers were improved by two methods for mixed cropping with balsam pears, which have compatible growth stages with cucumbers. The two methods were as follows: (1) mixed cropping of six cucumbers and six balsam pears alternately planted in the same ridge, which improved the yield and ratio of high quality cucumbers per stock about 7% and 6%, respectively, over a control with cucumbers grown alone; (2) mixed cropping with balsam pears planted perpendicular to cucumber ridges as barriers, which improved the yield and ratio of high quality cucumbers about 10% and 11%, respectively, over the control. On the other hand, when a balsam pear stock was planted at each end of a cucumber ridge in mixed cropping, the yield of high quality cucumbers was a little higher than that of the control but the difference was not considered material. In other words, when the number of balsam pear stocks was small, the effect of mixed cropping on the yield of high quality cucumbers was hard to be seen. It was also noted that mixed cropping with balsam pears mitigated damage to cucumber leaves by anthracnose and feeding by cucurbit leaf beetles and balsam pears used as barriers decreased the number of aphids parasitizing cucumber leaves. However, what improved the yield and ratio of high quality cucumbers in mixed cropping with balsam pears was believed to be the protection of cucumbers from wind damage and consequent decreases in the number of wounded or bent cucumbers rather than the mitigation of pest damage.