MOVEMENT AND REMAINING CROP
PACKOUTS
FERTILIZATION OF RIO'S
SAPOTE FLY QUARANTINE
CURRENT SITUATION

MOVEMENT AND REMAINING CROP-

According to TVCC data as of March 22, fresh shipments of Texas citrus are at 83.4 percent of last season. Grapefruit is at 87.2 percent, early oranges at 79.1 percent, navels at 70.3 percent and Valencias at 40.7 percent. Both early and navel oranges should be finished, so these percentages apply to total fresh shipments with respect to all of last season.

As for the remaining crop to be harvested based on the USDA's crop estimates of February, Texas still has 17.2 percent of its grapefruit, 10.8 percent of its early and mids and 62.8 percent of its Valencias. Essentially, prior indications of a May end to the current season are on target, especially since remaining grapefruit is estimated at only 38,000 tons as compared to some 126,000 tons as of this date last year.

PACKOUTS-

The volume of grapefruit harvested is nearly 12 percent greater than last season at this time, but fresh shipments are down nearly 13 percent. What's the difference? In a word, packout. Eliminations to processing are nearly 80 percent higher this season at 72,200 tons as compared to 40,360 tons last year at this time. Looked at another (although imprecise) way, fresh utilization is currently about 61.1 percent of harvested production in comparison to about 75.7 percent last season. Last year's dismal returns are looking much better in comparing of the two seasons.

Why are packouts so much lower this season? I've looked at groves and I?ve spent some time on the elimination line. The usual causes of eliminations appear to be about normal; rust, rind blotch, mechanical damage (leafminer, windscar and other causes) and sheepnosing. Post-harvest decay has been more problematic this season. There appears to be more oversized fruit than normal, which is to be expected when production is on the low side of normal. As you know, oversized fruit is usually poorly shaped, puffy and has very coarse peel.

Coarseness of the peel, however, does not appear to be limited to oversized fruit this season, as a surprising amount of other sizes of fruit also exhibit severe coarseness or rough skin this season. Why? Inadequate rain and irrigation come to mind, along with extremely hot, dry spring and summer. Too, I suspect that overfertilization may also be a contributory factor. That is to say that the full annual rate of fertilizer was applied pre-bloom, but fruit set came in a little below normal, which resulted in excess vigor-and excess vigor is detrimental to Rio grapefruit shape, size and peel texture.

FERTILIZATION OF RIO'S-

The preceding is not to say that growers routinely overfertilize Rio Red grapefruit. Indeed, most have reduced fertilizer rates to produce a smoother peel texture and to reduce the severity of sheepnosing. However, lowered rates can still be too much if overall fruit set is reduced.

It doesn't take a brain surgeon to appreciate the benefits of splitting fertilizer applications to Rio Red grapefruit. Because of its known problems with fruit shape, sheepnosing and coarser peel texture (in comparison to Ruby-Sweet grapefruit types), and long-term drought-induced alternate bearing tendency, annual fertilizer rates should be based on the overall crop load.

However, pre-bloom fertilizer application does not permit an assessment of overall fruit set, so splitting the application is the only viable option to fertilizer based on the crop load.

In other words, apply only about two-thirds of your normal fertilizer rate pre-bloom, then wait until fruit set has occurred to decide whether or not the balance of the fertilizer is needed. Fruit set is established about mid-May, which is the time to apply additional fertilizer, if necessary.

If fruit set is about normal, go ahead and apply the rest of the fertilizer. If set is down, however, either forget about the balance or lower it substantially. Naturally, if set is substantially higher, put on the rest of the fertilizer and perhaps a little extra.

Yes, it takes a little more effort to assess the need and expense to make the second application. However, weigh that against the fact that Rio Red is unlike the other grapefruit varieties on which Texas' reputation for quality red grapefruit is based. I don't think we can continue to try to grow Rio's under the same production practices as Ruby- Sweet-practices which were developed, tested and proven over the years on those varieties.

SAPOTE FLY QUARANTINE-

Perhaps due to optimism, there was a rumor that the sapote fruit fly quarantine would be lifted in early April. It isn't true. According to USDA-APHIS, the quarantine cannot be lifted until three generations or life cycles of the fly have passed with no new finds. Given that the cooler weather this spring slowed the fly's development, we are still in the first life cycle.

Moreover, even with a return to normal temperatures, there is simply no way that all three life cycles will pass before our season is over. Indeed, the latest best guess from APHIS is that it will be July before protocol requirements are met.

Consequently, any as yet unharvested fruit in the quarantine area must be fumigated with methy bromide or subjected to bait spraying (which takes time) in order to be moved into the fresh market. Alternatively, it can be sent direct to juice (not a really good option for grapefruit) or it can be abandoned. In the latter case, the amount abandoned should be appraised for crop insurance purposes. And, no, abandonment to a fruit fly quarantine is not an insured loss.

CURRENT SITUATION-

Bloom is finally ending, having started later and lasted longer than normal. Given the amount of bloom, the potential set is phenomenal, if we are able to properly care for the trees.

Irrigation will become a priority concern, as maximum fruit set and maximum cell division (which establishes potential fruit size) occur during the next six to seven weeks. Any moisture stress to the trees during this critical time will negatively impact both set and ultimate size potential.

Post-bloom pest control efforts are already underway (Temik® applications) or soon will be (orchard sprays). While most growers practice pest management, there will be no Integrated Pest Management scouting program this season, so those growers who have always used the program will have to rely on their own or other scouting efforts.

JULIAN W. SAULS, Ph.D.
Professor & Extension Horticulturist
2401 East Highway 83
Weslaco TX 78596