Effects of night temperature upon the development of some crop plants (preliminary).

Abstract

The effect of night temperature upon the development of some crop plants was observed, taking wheat, barley, rye, pea and french bean as test object. Each plants which sowned at suitable season were adequately managed. Those plants were cultured to the date of harvest in two green houses, the one being heated during night time to raise the night temperature average 4°C. higher than the other (control) (Fig. I). The plants in both green houses were investigated with regard to the growth rate, flowering and fruiting habit; Some of the interesting observations are recorded here. 1). Effect upon the growth rate: Warm night, generally, were promoted the growth of the plants, but could not give influence to the leaf number (Tab. 1). French bean, however, were slower in opposition by warm night (Fig. 5). The growth of ovary of pea were promoted by warm night. (Fig. 4). 2). Effect upon the heading and flowering: The heading of wheat, rye and barley were promoted by warm night; the promotion of wheat were one month's duration, but other plants were seven to ten days (Fig.2). The flowering of pea var. AOTURUNASI were promoted by warm night, but var. KINUSAYA were delayed (Fig. 3). The flowering of red-flower french bean were clearly by warm night, or the flowering percentage was 40%, but at warm night was 0.29% (Tab. 4). And observed that the developments of pollen mother cell were retarded by warm night temperature (Fig. 6). 3). Effect upon the harvested materials: Some investigation of the harvested materials were operated only about wheat, barley, and rye. Those plants, generally, at warm night were retarded the organization of the spiklet; grain number, size of spiklet, etc., but the grains were clearly substantial (Tab. 1 & 2).