Shading and thinning of ribier grapes: a study of effects on soluble solids, maturation date and vigor

4'?a.*- M-IMtfj &BL4K^ #^4 .itft jk'•fe'tt *>/" epproxlmately mid July to mid September with one of two types of plastic saran shade material which reduced the total solar radiation to 70 and ^5% of full sunlight. Half of the fruit was removed from designated vines at the same time. The study revealed that shading prolongs the harvest date two to three weeks. On the August 19th date when the 8/A ratio of the fruit growing under the full sun was taken It was 24il. The B/A ratio of the fruit under 30* shad# and 55* shade was 17 tl and 15 J1 respectively. Pruning brush weights of the vines under 55* shade were about 19.6* less than the vines under full sun and 8.9* less than the vines under 30* shade, but the pruning brush weights were not significantly different from shaded vines with thinned crop. Pruit placed In cold storage from the shaded vines showed a higher degree of decay than fruit from unshaded vines. The experiments were Initiated to alter yield and light intensity and to observe the effects, singly and in combinations. The vines of V. vlnlfera, variety Hi bier were covered from % ,, « v - s- v v wn " S • .- "J