Fruit Growth and Thinning

Question 1

What is a fruit set

Answer 1

process of a flower forming a fruit. Occurs when successful fertilization occurs and initatess seed development

Question 2

When and what is flower drop?

Answer 2

During or shortly after full bloom defective flowers fall

Question 3

Which hormones in seeds affect fruit growth

Answer 3

Gibberellic acid and, Indole-3-acetic acid

Question 4

What is June drop

Answer 4

Physiological fruit drop caused by a shortage of carbohydrates in the tree, occurs 4-6 weeks after full bloom, April/May

Question 5

What causes June drop?

Answer 5

the trees have limited leaf area for photosynthesis but a lot of developing fruit all demanding carbohydrates to grow

Question 6

What cultural practices can be used to increase CHO availability to fruit?

Answer 6

Nitrogen is cruitcal to good fruit set, zinc and boron deficiency can induce abscission in almond, and water deficit can induce drop

Question 7

What happens if all fruit are left on the trees

Answer 7

Fruit will be small and poor quality; branches will break off or split, encourages pest and diseases, alternate bearing with no energy for producing flower buds

Question 8

What are the benefits of thinning?

Answer 8

improves the leaf-to-fruit ratio, reduces the overall weight of fruit, and limit disease

Question 9

Which fruit trees are thinned

Answer 9

Peaches, nectarines, plums, pluots, apricots, apples, and pears

Question 10

What factors effect thinning?

Answer 10

Variety, History of orchard site with variety, age, market demands from variety, degree of fruit set, severity of pruning

Question 11

what are the types of mechanical thinning?

Answer 11

mallet, string thinner, and trunk shakers

Question 12

What are the types of chemical thinning?

Answer 12

bloom period and post bloom, GA sprayed on foliage mid to later summer to inhibit flower bud development and subsequent spring bloom.

Question 13

Abscission

Answer 13

controlled process that in most cases is initiated during the development of the organ by the formation of an abscission zone, Ethylene accelerates this process

Question 14

Which chemicals cause thinning

Answer 14

ethephon- release ethylene gas, auxins- reduce photosynthesis, cytokinin decrease sugar translocation, and carbaryl- restricts vascular influx

Question 15

What is associated with the growth of fruits?

Answer 15

cell division and expansion of intercellular spaces

Question 16

What is associated with the growth of fruits?

Answer 16

cell division and expansion of intercellular spaces

Question 17

What is fruit growth and yield dependent on?

Answer 17

development processes (driving rates of fruit maturation and demand for carbohydrates and nutrients), and assimilation processes (determining the supply of carbohydrates and nutrients available to support growth and development)

Question 18

What determines fruit developmental processes

Answer 18

relative growth rate determines individual fruit growth potential and heat unit accumulation determines rates of fruit maturity