Manipulating transplant morphology to advance and enhance fruit yield in strawberry

Strawberry plants are vegetatively propagated in northern nurseries to supply fruit production farms in the southern United States of America. Digging actively growing plants in the fall from northern nurseries, and transplanting them into southern fields at a time of seasonally high temperatures makes it difficult for transplants to re-establish. Tall transplants are prone to leaf damage during shipping, and excessive leaf area causes more wilting after transplanting, leading to plant death in the southern fields. Improving strawberry plant morphology in the northern nurseries can produce more robust transplants, resulting in better post-transplant growth, higher fruit yields and earlier fruit production. Experiments to alter plant morphology used two methods: mechanical leaf removal by mowing, and chemical control using the growth regulator prohexadione-calcium. Two cultivars, 'Sweet Charlie' and 'Camarosa', were mowed in a nursery field in Nova Scotia (45° 26´ N, 63° 27´ W) on one of four dates (Aug. 22, Sept. 7, Sept. 22 and Oct. 5) during the growing season in 2000. Plants were dug on October 5, and transplanted in Dover, Florida (28° 00´ N, 82° 22´ W). Fruits were collected twice weekly from late November, 2000 to mid-February, 2001. Mowing reduced plant height and total leaf area. At time of digging, plants which were mowed later were shorter than those mowed earlier. By the end of December 'Camarosa' plants mowed on Sept. 7, had produced 51 % more fruit by weight than the unmowed controls; total yield (to mid-February) was increased by 20%. Plants of 'Sweet Charlie' treated with prohexadione-calcium on Sept. 7 in Nova Scotia were more compact, and in turn produced 29 % more fruit by weight by the end of December, and greater total fruit yield (18 %) relative to non-treated transplants in Florida