"Perfect timing" for early summer rain over interior of South Africa"

Summer rains that have arrived early this year, complemented by mild temperatures and a higher relative humidity, couldn’t have come at a better time for many fruit growers across the interior of the country.

For many crops, such as macadamias, mangos and avocados, the period of flowering is over and now is the critical time of fruit set.

Dr André Ernst of Allesbeste Boerdery outside Tzaneen, Limpopo Province, says that it’s not only the rain, which moistens more evenly than irrigation, that has been most welcome, but also the temperatures in a milder range coupled with relative humidity of about 55 to 60%.

These conditions remind avocados of home. “It is ideal not to have unnecessary fluctuations in temperature and relative humidity during this period and the current weather will definitely be a boon to the avocado season.” He continues: “We’re in a very good position as we approach the first period of fruit drop and one can already see that fruit set looks really good.” 

Athol Currie, chairperson of the South African Avocado Growers’ Association and based in KwaZulu-Natal, says: “Judging by the flowering there could be a big avocado crop. We’re very positive. The rain came with perfect timing for us.”

“The timing of the rain was fantastic,” agrees Theunis Smit, macadamia horticulturalist for Mayo Macs in Mpumalanga. “Last year our first rains in the Lowveld only came about mid-November. The flowers were somewhat earlier this year in the Lowveld, the fruit set was a bit earlier too – the nuts are now between the size of the head of a matchstick and a pea. The fruit set really looks good and it’s interesting: we find that in years when the yield is up, the quality is up too.” 

Macadamia farmers in Limpopo hope that these milder conditions will provide some respite from the thrips that have thrived under the hot, dry conditions of last season.

Two weeks ago, before these good rains, hail hit some Hoedspruit mango farms towards the northern Drakensberg. Jaco Fivaz of Mohlatsi Farms says that a warning issued by a crop insurer of an impending hailstorm went out on the farm watch and three minutes later hail came, accompanied by barely any rain, either before or after.

It is estimated that 150 to 200ha was hit, with damage between mango orchards varying between 20% and 80%, resulting in perhaps 10% of the damage wrought by the 2015 hailstorm which occurred six weeks later in the season. 

Much of the damage consists of marks on the small fruit, but in some cases all young fruit were removed. It’s reckoned to affect around 1,000t of mangoes coming from the Hoedspruit area, where average yield is 20t/ha. (Citrus orchards in Hoedspruit are fortunately in a pre-fruit set stage and flowers that were dropped by the hail, can merely be replaced by others.)

No such problems for mango growers in Tzaneen, where a winter on the warm side has had a dampening influence on flowering but the rain has nevertheless come at a welcome time.

In Komatipoort there are still water restrictions and Pieter Buys, chair of the South African Mango Growers’ Association, says that that could still have an influence on their harvest, which is expected to be around 70% of the normal harvest.

South Africa’s first table grapes of the season, coming from the Groblersdal and Marble Hall areas, are nearing harvest. White grapes will be picked from week 43 or 44. The cooler temperatures, of about 25°C to 30°C, have provided good growing temperatures in a region where a month ago springtime temperatures were close to 40°C. 

Cooler conditions will be good for colour development on the grapes. An added advantage is the acclimatisation of the grapes to cooler, moist conditions; rain at harvest would have a harsher effect if it were to come after a hot and dry spell.

In KwaZulu-Natal, where a severe storm around Durban killed at least eight people and Durban Harbour was closed, banana, avocado and macadamia farmers who are situated inland from the coastal city, don’t report significant damage apart from slight hail. Some areas in KZN received from 130mm to 220mm over 48 hours.

Cold temperatures as a result of snow over the mountains in the eastern part of the country have raised the risk of frost but the moisture left by good rain has lessened the danger. Apple orchards in Mpumalanga and the eastern Free State are at the end of flowering where fruit set looks promising. There, too, a relatively warm winter delayed the trees in breaking bud. 

In some areas, like Fouriesburg, last year some orchards were completely knocked out of the season by frost, so they are relieved to have escaped the recent weather events without frost damage.

It is a sensitive time of the year for apple trees, but the risks related to fruit set look to have been obviated. Hail remains an ever-present risk and therefore many of the apple orchards in this northeastern production region are covered by hail netting.