It will help to promote growth of robust shoots early in the season and to maintain good fruit size during the harvest period. Irrigation should be started before plants show signs of wilting. The amount of water required by brambles varies with weather conditions, plant stand, and plant vigor. However, the maximum or peak moisture-use rate is considered about 0.20 to 0.33 inch per day. Brambles obtain practically all their moisture from the top two feet of soil.
Soils vary in the amount of water that they can hold in the top two feet.
For example, well-drained sandy soils may hold only two inches of water, and loams may hold up to four inches. It is generally considered that irrigation should be started when 50 percent of the available moisture in the soil has been used. It can be seen that with peak-use rates, this situation would occur in five to 10 days, depending on the soil type and rainfall. When the soil will not hold together in a firm ball when squeezed, the moisture content has dropped to a stage where irrigation should be started. A ball that is sticky when squeezed contains enough moisture.