My tomato plants are about 5 foot tall and appear to continue to gain height. My problem: the flowers bud out nicely then dry up and literally fall off before ever becoming a tomato. I have had success in the past with where they are planted and I use a granual fertilizer designed for tomatoes. The photo/file shows the flower in the foreground is already dead while the flowers behind it appear to be normal.
Blossom drop can be attributed to several causes, most often related to either temperature and /or stress.
1. Temperature: Extreme temperature such as high daytime temperatures (above 85 oF/29 o C), or high nighttime temperatures (above 70 o F/21 C), or low nighttime temperatures (Below 55 o F/13 o C) tomato plants will drop the flowers. Tomatoes grow best if daytime temperatures range between 70 o F/21 o C and 85 o F/29 o C. While omato plants can tolerate more extreme temperatures for short periods, several days r nights with temps outside the ideal range will cause the plant to abort fruit set and ocus on survival (Mills, 1988). Temperatures over 104̊o F/40o C for only four hours an cause the flowers to abort. If the night temps fall below 55 o F or rise above 75 o or if the day temps are above 85o F, the pollen becomes tacky and nonviable. ollination cannot occur. If the bloom isn't pollinated, the bloom dies and falls off. hemical growth regulators can sometimes help overcome low temperature effects, ut the resulting fruit is usually seedless and of poor quality.
2. Humidity: The ideal humidity range is between 40 70%. f humidity is either too igh or too low, it interferes with the release of pollen and with pollen’s ability to tick to the stigma. So pollination will not occur. If humidity is too low, hose the oliage during the day. This will both cool the plant and raise the humidity. This is not ecommended in areas with high humidity or when fungus diseases are present.
Other potential sources of blossom drop:
1. Lack of pollination: Tomatoes need some help to pollinate. Insects, wind or hand haking of the flowers is necessary to carry the pollen from the anthers to the stigma. uring extremes weather conditions, there are often no insect pollinators.
2. Nitrogen: High or low application rates of N fertilizer can cause blossom drop. High rates ofnitrogen fertilization encourage lush vegetative growth and inhibit flower roduction and/or pollination, resulting in poor fruit set. Low N produces spindly vines wth low food reserves that cannot support a crop.
3. Lack of water: Tomatoes have very deep roots, and can sometimes reach down up to 5 feet Shallow watering will stress and weaken the plants. The root zone should be uniformlymoist throughout the growing season to develop a large, healthy root system.
4. Insect damage or disease: Use good cultural practices and treat for disease as soon as symptonsappear. Fungal diseases such as botrytis or heavy bacterial spot or speck pessure can often cause flowers to abort.
5. Heavy fruit set: When a tomato plant has too many blossoms, the resulting fruits are allcompeting for the limited food supplied by the crop. The plant will automatically abortsome flowers. Once the initial crop is harvested, the problem should subside.