Great care must be exercised to avoid over-hardening of tomato plants, for in this way a check in growth is incurred from which they recover slowly, and perhaps never fully.
Much study has been given to the changes in plants which underlie the hardening process, and papers by Harvey, Rosa, Loomis, and others should be consulted in this [connection.]
Figure 14.—Plants that have been crowded and overgrown, probably undernourished and over-hardened. Plants like this are very often set in the field. They are definitely slow in starting growth.
Watts[15] has shown that adverse conditions, especially low temperature and water deficiency prevailing at the time when fruit clusters are barely beginning to form, commonly occasion the development of misshapen fruits.
Faithful spraying or dusting with Bordeaux in the plant bed has proved a useful means of forestalling destructive leaf blights which often devastate whole fields.